The CNC mills have revolutionized small production runs. For example, it used to be very hard to restore old cars for which parts were no longer available. For example, decades ago a guy down the street restored some old Mercedes limousine he showed me, and I asked him how he dealt with the unavailablity of parts. He said "oh, I just made them" and showed me his fully equipped machine shop in his basement.

That can now be done with a simple CNC machine.

A lot of shops have sprung up that apparently have libraries of CNC designs, and they manufacture the parts on demand.